Have you heard how people are doing in terms of sales for their apps in the Google App Market?
Lousy, for any number of reasons:
No major media attention, as opposed to iPhone App Store rollout, so non-developers may not even realize there is a changeThere are "only" a million or so devices out there, so unless you have an app that everyone needs, you won't get many sales just based upon sheer statisticsDevelopers saw the "land rush" that was the iPhone App Store, and assumed they could just write an app and have it sell lots of copies, without bothering with pesky things like "marketing" or "promotion" or "public relations"The Android Market is only available to users in some countries, cutting into the overall user baseThe Android Market is not available (at present) to users with ADP1 developer phones, cutting into the overall user baseEtc., so on, and so forth
Developers have a bit of "irrational exuberance" -- many fail to realize that the iPhone App Store was a once-in-a-decade sort of event and not everything will behave quite like that. Selling dozens of copies a week with no marketing effort is pretty impressive in just about any other market...but at a few dollars per copy, developers will not get rich.